Most palms tend to be very tolerant of fertilizer. I would try it. I give my Majesty palm lawn ferilizer by the handfull on a weekly basis and it only grows faster.

Aside from mail ordering expensive palm - specific palm fertilizers, is there something I can get at a garden center (HD or Lowes, etc ) for my hardy palms? Would a Miracle Grow type product help, hurt or no effect?

I personally use 3 products on all my palms

miracle grow slow release 10-10-10 (any slow release 10-10-10 is good)

On fast growing palms that can tolerate it and cycads I use
27-2-1 (i think) lawn fertilizer (without added pesticides or weed killers)

I also give all my palms epson salt. It keeps them dark green and provided them with magnesium.

How much Epsom salt? Frequency?

Lawn fert? Really? I give that to my bananas.

10-10-10 is a good generic slow release for lawn and garden. I broadcast that into my beds at the beginning and end of the season. It makes sense palms would benefit from it. Still curious about the Epsom salt.

Need to be careful with high N fertilizers.....
very easy to burn Banana,EE leaves-etc.

You cant let the high nitogen fertilizer stay in contact with leaves or rrots. You must wash iot down so its dilute. I give it to my bananas too.

I just sprinkle epson salt around the base of the palm and water it. I put it in the soil once or twice a year.